Okay so let me tell you about the tree lobsters.
They're these behemoth weird bugs, like crickets as big as your hand. They live in the trees and don't do much, they just muck around trying to find food like every other peaceful species. When rats arrived on their little island they had a holocaust; they just weren't equipped for it in any way. The islanders honestly didn't seem to mind very much; they were kind of off putting creatures and did nobody any good in particular. Everyone thought they were extinct, oh well, I have work tomorrow and things on my mind.
Not the biologists. They heard a rumor that a little population might have hung on, way out on some godforsaken spire of rock out on the water that was too far away from the island for anyone to care about. They went out there, in bad weather, more than once, put genuine risk to their safety having to climb up like mountaineers up this massive sheer rock spike; eventually they realized they had to go at night, out on the water, and they kept at it until they actually found a few of the damn things alive, and brought them back to try to set up a little breeding population.
Most of the them died. No one really knew what to feed them but they managed to figure it out just barely in time. Out of 4 they brought back from the dwindling population, 2 died, leaving 2: 1 male and 1 female. To hear the scientists talk about it and how panicked they got about this being for real the last chance that these unique little creatures might have, that their whole lineage might live or die depending on what this little handful of people in the lab can figure out or how hard they try to make sure they get what they need to keep living, honestly gets me a little choked up thinking about it. Anyway, they're still around, and producing eggs and little babies now.
To me -- I am dead serious about this -- this is part of what I love about humanity. For as much fucked up stuff as we do I do not know of any other species that would do something like this. The whole unique combination of caring enough to risk your safety and spend years of effort, a significant chunk of your one and only life, and this level of intelligence and talent and shared knowledge, all invested in some weird little beasts that can't really do anyone any good at all. It's just, oh shit, they're in trouble, real bad trouble and we can help them so we have to.
Things go extinct all the time. Mother Nature doesn't give a shit any more than Shell Oil does. But now these little guys have temporarily someone to look after them who really cares, for maybe the first time in their whole species' lifetime.
At least as far as I know they are still around. They tried to introduce them back to the island, which is difficult, and which the island's inhabitants may or may not want, but the lab still has a bunch of them. They're still around for now.
Edit: Corrected some details